Public-key encryption system

A public key encryption method for encrypting an electronic message using a public key performed by resource-constrained devices such as a sensor, a lighting device, a LED lamp, a smart card, or an RFID tag within a lighting network, the public key comprising a public univariate polynomial and a public set of bivariate polynomials, wherein a different commutative ring is associated with each polynomial of the public set of bivariate polynomials,

• said public key encryption method comprising:
• obtaining, in electronic form, an encrypting random value;
• computing a symmetric key by substituting the encrypting random value in the public univariate polynomial;
• computing a decrypting univariate polynomial by summing over univariate polynomials obtained by substituting the encrypting random value into the polynomials of the public set, the univariate polynomial obtained by substituting the encrypting random value into a particular polynomials of the public set is reduced to a canonical form in the commutative ring associated with the particular univariate polynomial;
• generating the decryption information, the decryption information comprising the decrypting univariate polynomial;
• and
• encrypting the message with the symmetric key and associating said encrypted message with the decryption information.

A computer program embodied on a non-transitory computer-readable medium, comprising computer program code for causing a computer, when the computer program is run on the computer, to perform a public key encryption method for encrypting an electronic message using a public key performed by resource-constrained devices such as a sensor, a lighting device, a LED lamp, a smart card, or an RFID tag within a lighting network, the public key comprising a public univariate polynomial and a public set of bivariate polynomials, wherein a different commutative ring is associated with each polynomial of the public set of bivariate polynomials,

• said public key encryption method comprising:
• obtaining, in electronic form, an encrypting random value;
• computing a symmetric key by substituting the encrypting random value in the public univariate polynomial;
• computing a decrypting univariate polynomial by summing over univariate polynomials obtained by substituting the encrypting random value into the polynomials of the public set, the univariate polynomial obtained by substituting the encrypting random value into a particular polynomials of the public set is reduced to a canonical form in the commutative ring associated with the particular univariate polynomial;
• generating the decryption information, the decryption information comprising the decrypting univariate polynomial;
• and
• encrypting the message with the symmetric key and associating said encrypted message with the decryption information.